engleski

Wheat starch

The main component of wheat is starch, which constitutes 63 – 72 % of wheat grain (d.m.). Wheat flour, produced by wheat grain milling, is major ingredient in most European breads and pastries. Since part of the grain is removed during production of flour, starch content in flour rises to app. 80 % d.m., and in bread it averages around 50 % of total bread mass. Starch is main source of energy in human diet. Therefore, it is very important to understand its properties and changes it undergoes during processing, as well as its physiological effects and influence of botanical source on these characteristics. It is well known that starch constitutes of two polysaccharides: linear amylose and branched amylopectin, organised in granules of different sizes and shapes, depending n botanical source. The cluster model of organisation of amylose and amylopectin is widely accepted. However, its chemistry, biochemistry, genetics, processing and modifications, as well as behaviour of starch and starchy materials in different thermodynamic conditions, although revealed to some extent, are still object of many researches and are not yet fully understood. This chapter will deal with isolation of starch from wheat and its characterisation. The first part of book chapter will give literature review of different processes of starch isolation from wheat and its properties, while in the second part of chapter laboratory isolation of starch from two Croatian wheat varieties (Golubica and Srpanjka) and results gained by its characterisation will be presented. Properties of starch: gelatinisation, retrogradation, pasting properties, swelling capacity, gel texture, resistant starch content etc. will be discussed.

wheat starch ; gelatinisation ; retrogradation ; pasting properties ; swelling capacity ; gel texture ; resistant starch content

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